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题型:阅读选择 题类:模拟题 难易度:普通

    Have you ever rubbed your hands together when they get cold? Why do we do that? We do that for friction. Friction happens when two things that aren't very smooth (光滑的) rub together to make heat energy. The faster you rub two things together, the more friction you can make. Let' s discover friction!

WHAT YOU'LL NEED:
★Soap                ★Water           ★Your hands
WHAT TO DO:
★Make sure your hands are dry.
★Rub your hands together until you feel the heat of your hands.
★Now, use soap and water to get your hands very slippery (滑的).
★Try to make friction happen while your hands are slippery.
★Please write down what has happened.
LET'S TALK!
    Friction is an energy that happens when two things rub together. When friction happens, it makes heat! When your hands are slippery, they won't make very much friction and your hands won't get so hot.
DID YOU KNOW?
★Friction happens when you stop your fast running bike.
★Ancient people made fires by rubbing two pieces of wood together. Friction happened though they didn't know it. ___  __?         Friction is everywhere. Have you ever noticed situations where friction is happening? If not, ask your parents to take you out in a car. If it is not hot, touch the tires (轮胎) of the car before and after a short drive to see how much warmer they get from friction.

(1)、You'd better make your hands ______ to get heat when you rub them.

A、slippery  B、dry  C、wet    
(2)、The word “friction” in the first paragraph means “______”.

A、摩擦          B、震动  C、膨胀 
(3)、We can know from the passage that it's a ______ experiment.

A、physics B、chemistry        C、biology
(4)、The topic of the last column (栏目) is ______

A、THINK IT OVER!   B、WHAT HAPPENED?   C、WORK WITH PARENTS.
(5)、The main idea of the passage is ______.

A、how to discover friction   B、how to rub your hands  C、how to make fires by rubbing   
举一反三
   Ask someone what they have done to help the environment recently and they will almost mention recycling, which is the process (过程) of treating used things, such as paper or steel so that they can be used again. Recycling in the home is very important of course. However, being forced to recycle often means we already have more things than we need. We are now dealing with the results of that over-consumption in the possible greenest way, but it would be far better if we did not bring so many things home in the first place.
   Here is an example. In the UK, the total of packaging increased by 12% between 1999 and 2005. It now makes up a third of a household's waste. In many supermarkets, foods are packaged twice with plastic and cardboard.
   Too much packaging causes serious environmental problems. The UK is running out of different kinds of ways for dealing with this unnecessary waste. If such packaging is burnt, it gives off greenhouse gases which go on to cause the greenhouse effect (效果). Recycling helps, but the process itself uses energy. The best way of avoiding this problem is to stop producing such unnecessary things in the first place. Food waste is another serious problem, too. Too many supermarkets encourage customers (消费者) to buy more than they need. They seldom encourage customers to reuse their plastic bags, for example. However, a few of them are coming round to the idea that this cannot continue.
   But this is not just about supermarkets. It is about all of us. We have learned to connect packaging with quality (质量). We have learned to think that something unpackaged is of poor quality. Is it true for all the products? In fact, more and more companies realized the importance of protecting the environment. They try to package what really should be packaged, including products in good quality.
   As more of us recycle, we are beginning to realize how many unnecessary things are being collected. We need to face the waste of our daily life. Although many people have taken action to recycle, we have a high mountain to climb.

Carbon monoxide poisoning (一氧化碳中毒) causes death and injuries around the world. This gas is a problem in all parts of the world that experience cold weather. A few years ago, America's Centers for Disease Control (C. D. C.) studied deaths linked (联系) with carbon monoxide poisoning. It found that the number of carbon monoxide deaths in the United States was greatest in January. The C.D.C. also found that carbon monoxide kills more than four hundred Americans each year. And, it said more than twenty thousand people are taken to hospital for treatment of health problems linked with the gas.
Carbon monoxide is called the silent killer because people do not know it is in the air. The gas has no color, no taste and no smell. It does not cause burning eyes. And it does not cause people to cough. Yet, carbon monoxide gas is very deadly (致命的). It steals the body's ability to use oxygen.
Carbon monoxide makes it difficult for the blood to carry oxygen to body tissues (血管). It does this by linking with the blood. When the gas links with the blood, the blood is no longer able to carry oxygen to the tissues that need it. Damage (损害) to the body can begin very quickly from large amounts (数量) of carbon monoxide.
How quickly this can happen depend on how long a person is breathing the gas and how much gas he or she breathes in.
Carbon monoxide poisoning has warning signs(标志). But people have to be awake to realize them. Small amounts of the gas will cause a person's head to hurt. He or she may begin to feel tired. Their stomachs may feel sick. The room may appear to be turning around. The person may have trouble thinking clearly.
People develop serious headache as the amount of the gas continues to enter their blood. They will begin to feel very tired and sleepy. They may have terrible stomachache.
Doctors say carbon monoxide influences people differently. For example a small child will experience health problems or die much sooner than an adult. The general health of the person or his or her age can also be important

 请阅读下面短文,根据所提供的信息,回答5个问题。要求所写答案语法正确、语义完整切题。

Most people have heard of the Great Wall of China, but not many people outside of China know about the Grand Canal(大运河).This manmade waterway, known in China as Da Yunhe, is 1,700 kilometres long and some parts of it are more than 2,000 years old.It links(连接) the north of China with Hangzhou, a city in the southern part of the country.It's the longest manmade waterway in the world.

 It was built as a way to transport food from the rich land in China's south to cities in the north.In fact, it's not one canal, but a system of canals and rivers linked together.

It's still an important part of the transport system in China.Thousands of boats use it every day to transport food and many other kinds of things.

China is now doing new work on the Grand Canal.It is making part of it deeper, so bigger ships can pass.The canal will also help to move water.There is a lot of rain in the south of China, but not so much in the north.The canal will carry lots of water from the south to the north.

The Grand Canal is much less famous than the Great Wall, and not very many visitors know it.But it sees the changes in Chinese history.It's possible to go on a trip along some of the oldest parts of the canal.Visitors can see beautiful parts of China that others don't see.

How long is Da Yunhe?

信息匹配

What is the most stressful thing in school? It is probably exams. Exams can put us under a lot of pressure. But some students do well under pressure while others feel terrible. {#blank#}1{#/blank#}

It all comes down to dopamine (多巴胺). {#blank#}2{#/blank#} It has many important roles: influencing memory, attention. and how we learn. Our brains work best when there is an even balance of dopamine—not too much or too little. The brain controls dopamine in two ways. It either takes out dopamine quickly, or gradually. Exam success can be related to how fast dopamine goes back to an even balance.

 {#blank#}3{#/blank#} if you become stressed, your brain will start to have too much dopamine. {#blank#}4{#/blank#} The quicker you are able to go back to an even balance of dopamine, the quicker you can fix yourself perform better on a test. 

Scientists found that, during a test, people who slowly got back to an even balance of dopamine scored 8 percent lower. {#blank#}5{#/blank#} The answer is yes. So don't fear, there is some good news. The study also found that the more practice you get, the less stressed you'll be. So, it turns out that practice really does make perfect.

A.What happens when we sit for an exam?

B.It is like a cup flowing over with water.

C.So, why do some students perform better under stress?

D.That's the difference between a good mark and a bad mark.

E.Dopamine is a chemical in our brain that sends information to our body.

F.Is there anything that can help change the speed of dopamine getting into our body?

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